The calpain enzyme system plays an important role in the proteolytic events leading to the conversion of muscle to meat in livestock species. Increasing evidence suggests that calpastatin, the inhibitory component of the system, correlates negatively with tenderness in beef and pigs (Koohmaraie et al., 1995; Sensky et al., 1998). In this study, the immunoreactivity of calpastatin in three pig breeds with different meat quality traits have been measured.
Thirty-six female pigs, comprising equal numbers of Duroc (D), Large White (LW) and Duroc x Large White (50:50 DxLW) breeds were reared under identical conditions at a commercial pig unit and slaughtered at a commercial slaughterhouse on the same day by electrical stunning and severance of the carotid arteries. Carcass weight, backfat thickness, pH45 and pHu were all monitored.